Oops, reverse previous default guess

restore our historical guess for debug/release -- this prev PR breaks other assumptions (e.g. google builds).

Mostly just means we need to explicitly set NDEBUG in our Schemas for Xcode when we want a release build. (Xcode sets DEBUG for those builds, but --nothing-- in release builds)

Diffs=
953abb538 Oops, reverse previous default guess
diff --git a/.rive_head b/.rive_head
index 59fd6b2..9e701f7 100644
--- a/.rive_head
+++ b/.rive_head
@@ -1 +1 @@
-8d6da9a325e1d11d61fa1bede1e5360ff5df95ae
+953abb538511908461618aac4edecf68b28c58bb
diff --git a/include/rive/rive_types.hpp b/include/rive/rive_types.hpp
index 9624bb0..13fb53b 100644
--- a/include/rive/rive_types.hpp
+++ b/include/rive/rive_types.hpp
@@ -17,8 +17,12 @@
 
 #if !defined(DEBUG) && !defined(NDEBUG)
     // we have to make a decision what mode we're in
-    // xcode seems to be in Release mode in this case ...
-    #define NDEBUG  1
+    // historically this has been to look for NDEBUG, and in its
+    // absence assume we're DEBUG.
+    #define DEBUG  1
+    // fyi - Xcode seems to set DEBUG (or not), so the above guess
+    // doesn't work for them - so our projects may need to explicitly
+    // set NDEBUG in our 'release' builds.
 #endif
 
 #ifdef NDEBUG